Anyone who has watched crows, jays, ravens and other members of the corvid family will know they're anything but "birdbrained."

For instance, jays will sit on ant nests, allowing the angry insects to douse them with formic acid, a natural pesticide which helps rid the birds of parasites. Urban-living carrion crows have learned to use road traffic for cracking tough nuts. They do this at traffic light crossings, waiting patiently with human pedestrians for a red light before retrieving their prize.

Yet corvids may be even cleverer than we think. A new study suggests their cognitive abilities are a match for primates such as chimpanzees and gorillas. Furthermore, crows may provide clues to understanding human intelligence.

Published tomorrow in the journal